module.exports = {
  presets: [
    // https://github.com/vuejs/vue-cli/tree/master/packages/@vue/babel-preset-app
    // ["@vue/cli-plugin-babel/preset"],

    [
      "@vue/cli-plugin-babel/preset",
      {
        useBuiltIns: "entry",
        corejs: "3.25",
      },
    ],
  ],

  plugins: [
    // 参考资料 https://www.cnblogs.com/qingyanxd/p/15937005.html
    //可选链 ?.
    "@babel/plugin-proposal-optional-chaining",
    //空值合并 ??
    "@babel/plugin-proposal-nullish-coalescing-operator",
  ],

  env: {
    development: {
      // babel-plugin-dynamic-import-node plugin only does one thing by converting all import() to require().
      // This plugin can significantly increase the speed of hot updates, when you have a large number of pages.
      // https://panjiachen.github.io/vue-element-admin-site/guide/advanced/lazy-loading.html
      plugins: ["dynamic-import-node"],
    },
  },
};
